Add convenient API/CLI to prune all content

This is kind of a usability regression from
ostreedev@979b93a
"deploy: Add an API to prune undeployed images"

This new API and CLI make it convenient to prune the images,
the layers, *and* the underlying objects.

cc coreos/rpm-ostree#4720

This API in particular is what bootc wants.  For rpm-ostree
we do still want to separate pruning refs from objects, because
rpm-ostree may have layered packages, and we only want to traverse
the ostree repo to prune objects once.

ci/priv-integration.sh

@@ -58,13 +58,20 @@ for img in "${image}"; do
     test "$(($initial_refs - 1))" = "$pruned_refs"
     ostree admin --sysroot="${sysroot}" undeploy 0
     # TODO: when we fold together ostree and ostree-ext, automatically prune layers
+    n_commits=$(find ${sysroot}/ostree/repo -name '*.commit')
+    test "${n_commits}" -gt 0
+    # But right now this still doesn't prune *content*
     ostree-ext-cli container image prune-layers --repo="${sysroot}/ostree/repo"
     ostree --repo="${sysroot}/ostree/repo" refs > refs.txt
     if test "$(wc -l < refs.txt)" -ne 0; then
         echo "found refs"
         cat refs.txt
         exit 1
     fi
+    # And this one should GC the objects too
+    ostree-ext-cli container image prune-images --full --repo="${sysroot}/ostree/repo" > out.txt
+    n_commits=$(find ${sysroot}/ostree/repo -name '*.commit')
+    test "${n_commits}" -eq 0
 done
 
 # Verify we have systemd journal messages

lib/src/cli.rs

@@ -325,6 +325,10 @@ pub(crate) enum ContainerImageOpts {
         #[clap(long)]
         /// Also prune layers
         and_layers: bool,
+
+        #[clap(long, conflicts_with = "and_layers")]
+        /// Also prune layers and OSTree objects
+        full: bool,
     },
 
     /// Perform initial deployment for a container image
@@ -1005,25 +1009,40 @@ async fn run_from_opt(opt: Opt) -> Result<()> {
                 ContainerImageOpts::PruneImages {
                     sysroot,
                     and_layers,
+                    full,
                 } => {
                     let sysroot = &ostree::Sysroot::new(Some(&gio::File::for_path(&sysroot)));
                     sysroot.load(gio::Cancellable::NONE)?;
                     let sysroot = &SysrootLock::new_from_sysroot(sysroot).await?;
-                    let removed = crate::container::deploy::remove_undeployed_images(sysroot)?;
-                    match removed.as_slice() {
-                        [] => {
-                            println!("No unreferenced images.");
-                            return Ok(());
+                    if full {
+                        let res = crate::container::deploy::prune(sysroot)?;
+                        if res.is_empty() {
+                            println!("No content was pruned.");
+                        } else {
+                            println!("Removed images: {}", res.n_images);
+                            println!("Removed layers: {}", res.n_layers);
+                            println!("Removed objects: {}", res.n_objects_pruned);
+                            let objsize = glib::format_size(res.objsize);
+                            println!("Freed: {objsize}");
                         }
-                        o => {
-                            for imgref in o {
-                                println!("Removed: {imgref}");
+                    } else {
+                        let removed = crate::container::deploy::remove_undeployed_images(sysroot)?;
+                        match removed.as_slice() {
+                            [] => {
+                                println!("No unreferenced images.");
+                                return Ok(());
+                            }
+                            o => {
+                                for imgref in o {
+                                    println!("Removed: {imgref}");
+                                }
                             }
                         }
-                    }
-                    if and_layers {
-                        let nlayers = crate::container::store::gc_image_layers(&sysroot.repo())?;
-                        println!("Removed layers: {nlayers}");
+                        if and_layers {
+                            let nlayers =
+                                crate::container::store::gc_image_layers(&sysroot.repo())?;
+                            println!("Removed layers: {nlayers}");
+                        }
                     }
                     Ok(())
                 }

lib/src/container/deploy.rs

@@ -2,7 +2,7 @@
 
 use std::collections::HashSet;
 
-use super::store::LayeredImageState;
+use super::store::{gc_image_layers, LayeredImageState};
 use super::{ImageReference, OstreeImageReference};
 use crate::container::store::PrepareResult;
 use crate::keyfileext::KeyFileExt;
@@ -174,3 +174,47 @@ pub fn remove_undeployed_images(sysroot: &SysrootLock) -> Result<Vec<ImageRefere
     }
     Ok(removed)
 }
+
+/// The result of a prune operation
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Pruned {
+    /// The number of images that were pruned
+    pub n_images: u32,
+    /// The number of image layers that were pruned
+    pub n_layers: u32,
+    /// The number of OSTree objects that were pruned
+    pub n_objects_pruned: u32,
+    /// The total size of pruned objects
+    pub objsize: u64,
+}
+
+impl Pruned {
+    /// Whether this prune was a no-op (i.e. no images, layers or objects were pruned).
+    pub fn is_empty(&self) -> bool {
+        self.n_images == 0 && self.n_layers == 0 && self.n_objects_pruned == 0
+    }
+}
+
+/// This combines the functionality of [`remove_undeployed_images()`] with [`super::store::gc_image_layers()`].
+pub fn prune(sysroot: &SysrootLock) -> Result<Pruned> {
+    let repo = &sysroot.repo();
+    // Prune container images which are not deployed.
+    // SAFETY: There should never be more than u32 images
+    let n_images = remove_undeployed_images(sysroot)?.len().try_into().unwrap();
+    // Prune unreferenced layer branches.
+    let n_layers = gc_image_layers(repo)?;
+    // Prune the objects in the repo; the above just removed refs (branches).
+    let (_, n_objects_pruned, objsize) = repo.prune(
+        ostree::RepoPruneFlags::REFS_ONLY,
+        0,
+        ostree::gio::Cancellable::NONE,
+    )?;
+    // SAFETY: The number of pruned objects should never be negative
+    let n_objects_pruned = u32::try_from(n_objects_pruned).unwrap();
+    Ok(Pruned {
+        n_images,
+        n_layers,
+        n_objects_pruned,
+        objsize,
+    })
+}